1. Field of the Invention
The present invention relates to a nanoparticle having a shell with antibacterial property.
2. Description of Related Art
Nitrogen containing compounds including proteins have been used for a long time as a coating and painting material. For example, U.S. Pat. No. 3,943,252 teaches the use of leather dressing coatings based on plasticized casein and formaldehyde. Preservatives such as formaldehyde were used because they were deemed to reduce the water sensitivity of a nitrogen containing compounds such as casein. Because a protein such as casein possesses an inherent hydrophilicity, it is not water resistant, hence casein coatings are easily contaminated by bacteria. However, research has shown that the use of preservatives such as formaldehyde are disadvantageous because of the toxic nature of formaldehyde, leading to it having a negative affect of the environment and on the public health.
To address the concerns of the use of such preservatives, other preservatives such as ureas have been employed. However, as ureas have a tendency to breakdown to ammonia, these preservatives also are not suitable for products that may be edible or to be used for a substantial period of time.
In furtherance of attempting to avoid bacteria contamination of nitrogen containing compounds, especially proteins, the prior art has taught the production of nanoparticles containing such compounds in shells (see U.S. Pat. No. 6,573,313 to Li et al.). However, these efforts have failed to effectively reduce bacteria growth in substrates possessing such particles.
Therefore, new methods to improve the antibacterial property of coatings containing nitrogen containing compounds, such as casein, are needed.
It is an object of the present system to overcome these and other disadvantages in the prior art.